I wanted to have some decoration appearing out of the box when the lid opens so I decided to add a wooden laser-cut white star. I didn't make this, it came from a set of battery operated LED Christmas lights that I purchased in the clearance sale after Christmas. The LED lights were just push fixed into a double star so I unclipped the LED, separated one of the stars and worked out how to fix it to the lid. I wanted it to sort of dangle as the lid opened so I decided to use a pivot. By pure coincide the pivot I had already made for the lid opening mechanism seemed about right so I just printed off two more. I initially tried printing these together with the rafts overlapping, thinking the printer would be smart enough to work out a combined raft. I was wrong. It attempted to print both rafts so where they overlapped it became very lumpy and looked likely to fail. So I stopped that printed and used auto-place to fit the two parts in and printed that way. It worked OK, so I will not be overlapping rafts again on my 3D printer.
The wooden stars were just a little bit too large to fit inside the box so I used by cutters to remove the points, tided up the cut with a sharp blade and it is fine. For the dangling hinge mechanism I had to round off the corners so that they would rotate nicely. So after a bit of cutting and some sand papering they look OK and the star dangles, sort of. I hadn't realised that the centre of gravity would be behind the star so it dangles at an angle rather than straight down. I do not think there is anything much I can do about that.
I had some LED strip salvaged from a bathroom vanity mirror so I decided to stick a few of those inside the box. The strip is 12V so I have had to use an external power supply for that, but they are nice and bright so I will probably leave them. I had already decided that I wasn't going to be able to get the Arduino and batteries inside the box so I eventually gave-up and drilled some holes in the back, as suggested by Enrico Miginno. Below is the video showing these enhancements. The LEDs are turned down in brightness because the camera just overloads on white on full LED power and you just cannot see anything. It does work quite well in real life.
I will just spruce it up a bit now, maybe some more stars, more LEDs and see if I can get the sound part to work.